Dental casting machine



'May 23, 1940- A. P. vlczKEmsv 2,202,473

DENTAL CASTING MACHINE .Filed Oct. 14. 1937 yPatented May 28, 1940UNITED STATES PATENT OFFICE Q 2,202,473 i i .e DENTAL CASTING MACHNE nArchie P. Vickers, strani. Minn.

Application Octoberlfl, 1937, Serial No. 168,922 n l `s Claims. (ci.25a-65.1) I

My invention relates tocentrifugal casting machines of the type used inthe dental profession for casting inlays. i

The main object is to providea casting machine of compact and highly..efficient construc- Y tion and the use of which provides for quick andcompact casting of molten metal, or alloys', the device being'portableand self containedincluding a coily springy motor. i

The invention consists incertain novel combinations andv constructionofv parts wherein the above object is attained andas hereinafter fullyset forthreference being had to theY accompanying drawing, in which:

Fig. 1 is 'a side elevation'of my improved dental casting machine.

Fig. 2 is a bottom view of the rear end part of the motor housing of mydevice. f

Fig. 3 is a longitudinal sectional elevation of the motor housing andadjacent head part of the device. f y

Fig. flis a front view, showing the base 'I slightly in perspective andthe release spring housing IIA- in longitudinal section.

Fig. 5 is a cross sec-tional detail view of the crucible carrying arm ofmy device as'fon line 5--5 in Fig. 4 and Fig. 6 is a longitudinalsectional viewof the same parts as on line B-l'in Fig. '4.

Referring to the drawing by reference numerals, like parts beingdesignated by corresponding characters in the severalviews, I designatesa ilat, triangular base preferably a casting having an integral,central, upright boss 'IB bored vertically to receive the reduced andthreaded lower end of an upright or column 8 the lowermost end of whichis within a central pocket or recess 'IRl in the under side of the baseand Where a nut 8N is threaded on. One side of the base designatedIF isthe front and in a `plane at right angles thereto the upper part of thecolumn carries a rearwardly directed and elongated motorhousingdesignated 9.

Said upper part of the column comprises a hori- Zonta] hub 8H projectingforwardly and bored centrally and concentric of housing 9 to rotatablyand slidably retain a rotor shaft Il) the slidable or reciprocatingaction of which is limited. Forward of the said hub the shaft I isformed with a hubl IEEH carrying a pair of oppositely directed integralarms I I and I2, rotatable in a yver-f,v tical plane and over the frontface 1F of theV base, said arms carrying the casting 'means and acounterbalance therefor and rotation of which is accomplished by thespring motor means Within being. formed in therbar at vIZS to securelyclamp a downwardly directed hanger I5 .bored at its lower terminus toslidably receive va reciprocable Crucible release bar IB extendinghorizontally under bars II-I2` and parallel to them and being close totheunder side of arm Il. The outer end of said release rod I5 is formedwith a finger catch IGF in vicinity of the normal position of thecounterweight and remote from the Crucible on arm II said crucibleoscillated by direct manipulation ofsaid' rod I6. A Y

The arm II is preferably-integral of hub IIIH and its inner halfcomprises a straight rail on which the Crucible II is reciprocallyguidedon'a bearing I'IB vat Athe under sideof the Crucible. There isalso a pair of downwardly directed iingers IIli, on the crucible, andslidably engaging oppositesides of vtheA rail. y

Obviously the crucible II isthus rmly guided on top of the rail II, theCrucible being open upwardlyv and of box-like form.

The inner or receptacle part' I IR of the rucible is hollow and has anouter end outlet IIR.' concentric of an aperture I'IA in the outer endwall, I'IW of the crucible. `Itis a thumb screw threaded in the oppositelor inner wall of the Crucible v to clampy the receptacle part ofthecrucible in place rigidly. l

The outer part of arm Il, designated IIA is offsetv downwardly and itsfree end comprises an uprightl arm IIB` at the inner and upper part ofwhichis xed an inwardly flared disc I9 concentric of and in horizontallyregistering spaced relation lto the outer` end wall IIW of the Crucible.20 is a cylindrical -mold clamped by spring means between the Crucibleandthe disc I 9 and concentrically' of both. The flared .disc I9automatically'centers the end of the mold in it and it is obviousthatvarious sizes of cylindrical molds are likewise centered. y y

. The means for clamping the moldconsists of a tension coil spring 2|pocketed in a longitudinal bore fl ICin'the outer part IIA of the arm Ilandbeing in `continuous tension betweena threaded plug 22 in the outerpart of said bore and the threaded end part IST ofthe trigger rod I6,said latter threaded end being retained ina correspondingly threadedbore in the lower central part of bearing HB and under bar il (see Figs.l and 5). Thus the Crucible reciprocating bar i6 is rigidly Connectedwith the crucible, is slidably guided at itl and apull on the fingerhold part lliF (as to the left in Fig. 4) moves the crucible toward thehub and a mold lfl may be inserted or taken out of the space betweenparts i'lW and lll. The material in mold 2li is provided with the usualCavity 23 and a central passage 24 leading into the cavity from the endof the mold contacted by wall llW and registering with the aperturetherein. Gold or any other metal or alloy is melted in the hollow partof the crucible and is iorced int-o cavity 23, through outlet HR',aperture l'lA and passage 2li, by centrifugal force when the rotor isset in motion in anti- Clockwise motion as indicated by arrow 25.

Shaft iii, hub lill-l and arms liv-i2 are one integral structure andcomprise the rotor being set in rotary motion by a coil spring 25surrounding a rearwardly directed reduced part of the standard 8 andwhich comprises an elongated bearing for shaft lll the forward part ofthe spring 2li being xed in part 8H as at 26A, rear end of the springretained in a clutch 1nember 2l freely rotatable on shaft lll andadjacent the rear end of part 8B. The rearwardly ren duced part of saidclutch member has a number of circularly arranged clutch teeth SLlIengageable selectively by corresponding teeth 28T oi a clutch member .28fixed on shaft ill rearward of member 2. From. the latter Clutch memberthe shaft lll extends to and through the end wall of the cylindricalshell 9 Comprising the motor housing.

It will be readily understood that the entire rotor thus has a limitedend play or reciprocating movement.

Assuming now that melted metal is in the cru- Cible and ready forCasting, the rotary arms i l-i being in horizontal position, and thatspring 26 is coiled for action, the rotor is released from said positionby a reciprocable rod mounted parallel to and under housing il the frontend of said rod projecting into the path of an integrally formed radialwing iilW of the hub iii (latter position shown in Fig. 3, releasedposition in Fig. l). The Clutch members El-28 at this time areinfcontact spring unwinds, member El spinning member 28 which of coursespins shaft ill and entire rotor, the molten metal being forced bycentrifugal action intothe pocket 23.

The motor spring is wound up first by pressing forward the exposed rearend of shaft iti, thus connecting the clutchfmembers. This lorwardpressure causes hub itl-I to move forward as to dotted line position andprovides a space between said hub and the forward end of the stationaryhub 8H. The spring is wound up by merely turning the rotor in clockwisedirection as indicated by arrow 30 (Fig. e) and rotor is retained inposition with arms ii-EZ horizontal by merely moving rod 29 forward tocontact posin tion with wing iDW.

In construction of this device it is necessary that arm il, the Crucibleand mold be or" heat retaining material and yet of as light weight aspossible. I-Iitherto this has made it diiiicult to recast rapidlybecause of hot exposed areas. In this device the Crucible is moved awayfrom the mold to release the latter by the finger hold illF which isremote from the hot Crucible and mold, in fact an operator can place ahand with palm against the outer end of arm l2 and the Counterweight andwith one finger extended forward Contact and pull the release rod at56E' about in the way a hand is used for a pistol grip. The inwardmovement of the Crucible frees the mold and the latter may be allowed todrop out of the device.

The trigger rod hanger l5 and rod i6 may be of heat resistant materialto eliminate any possibility of burns by contact of the operators hand.

The Crucible arm i l is necessarily slightly oiset from the center ofhub iH but arm I2 extends directly radially therefrom, the Crucible,mold and entire Crucible arm being designed and positioned so as to beof about equal weight above and below a line drawn diametrically andConcentrically from the weight arm l2, thus providing a finer balanceand reducing or practically eliminating vibration when the rotor isspinning. rPhe features set forth in this and the preceding twoparagraphs are particularly stressed.

The entire casting machine is readily moved from one place to another byusing the motor housing as a hand hold or grasping the upright 8.

The triangular, heavy base positioned with one face at the front in aplane corresponding to the plane of the rotating arms l|-l2 furtherprovides for stability during the rotary Casting process.

After each rotary casting operation as above described the rotor isagain manipulated to wind up the motor spring and the rotor arms are setin the horizontal position shown in Fig. 4 preparatory to making thenext inlay.

Modiiications within the scope oi the above description and thestructure illustrated may be made without departing from the scope andspirit of the invention.

I Claim:

l. In a portable Casting machine of the class described comprising abase with an integral upright standard, an elongated horizontal housingextending rearwardly 'from the upper part of the standard and comprisinga handdoold and in part a rotor shaft journal; a rotor shaft capable oflimited longitudinal movement, the rear end of said housing being closedand bored to slidably retain the rear end of the rotor shaft projectingtheretl'irough7 a pair oi diametrically opposite arms integral of theiront end of said shaft, one arm a mold and Crucible retainer and theother arm a counterweight therefor, a helical coil spring about saidrotor shaft and having its forward ond fixed in the housing, a Clutchmember rotat ably mounted on said shaft engaging the rear end ci saidspring, a clutch member keyed on the shaft and close to said firstdescribed Clutch,

clutch means adapted to be engaged by forward movement of the rotorshaft to wind the rotor and its arms and coil the spring member asdescribed.

2. The structure specified in claim l, and a reciprocable rod mountedparallel to the motor housing and formed with a finger hold accessibleat the rear end of said housing, the other end of said rod adapted to bepositioned selectively in the path of the rotor arms or out of saidpath.

3. The structure specified in Claim l in which the protruding rear endof said rotor shaft comn prises a Contact member remote from theCrucible arm and adapted to be pushed forward and en gage the clutchmembers.

ARCI-IIE P. VICKERS.

